UPDATE: 05 September 2013 (later)

previously on 24 ...

Guy Lewis Steele's Wordsplit and the Reducers -
in which we applied GLS' algorithm on clojure.core.reducers/fold and learned some limitations.
We then used some trickery to batch-reduce text sections on fork/join and successfully split text in parallel.

But the final concatenation of segments was lazy. Realizing that laziness was costly, so costly as to nearly negate all parallel performance gains.

the turn

Realizing that laziness in the fork/join pool caused a lot of memory thrashing when combining segments.
To fix, we replace the combine with a reducers/cat.